A railway track typically has a pair of steel rails supported by a plurality of perpendicularly disposed ties that rest on a ballast material. Many railway tracks are located in remote areas where readily accessing the condition of a track may not occur if no known incident has occurred which may cause damage to the track. For example, railway tracks, or railways, may become damaged from storms or other natural occurrences, such as earthquakes, where the tracks may shift position. The shift can be caused by shifting ties and/or displacement of the ballast material. In other instances, such as where tracks are located adjacent to bodies of water, the ballast may shift or wash away resulting in the ties and hence the tracks shifting position. A track can also experience a shift due to a man-made accident, for example, a barge hitting a pillar or pillars supporting a bridge.
Similarly, with excessive pumping ties, in particular cement ties, can become damaged from beating against the ballast. Pumping ties are a condition caused by poorly maintained ballast material (rocks) under railroad ties. When a train wheel passes over the tie, the tie is driven down into the rocks. Once the wheel rolls over the tie, the tie rises out of the rock. The lowering and then rising of the tie can be many inches of travel. Wood ties allow for quite a bit of movement. However, when concrete ties are used, this pumping into the rocks causes the cement tie to chip away slowly on the bottom of the tie, which ultimately leads to early failure of the concrete tie.
Another occurrence that leads to train derailments and/or deaths is when automobiles (cars, trucks, buses, etc) stop on railroad crossings. Though locomotive engineers can visibly see when a vehicle is on a railroad track prior to reaching the vehicle, in some situations not enough time is available for the train to slow down and/or stop. When a vehicle is trapped by a crossing arm, situations result where the only way the vehicle can free itself is by running into and breaking the crossing arm. However, most drivers usually do not take such action.
If a train has a dragging car, caused by the wheels on the car malfunctioning or where the wheels have jumped the track due to a shifted rail, such incidences are not always immediately noticed. Failure to notice such an incident could result in a train derailment.
Such damage to a railway, blocking of a railway, and/or malfunction of a car on a train, can result in derailment of the train. With respect to railway damage, currently the best option to identify railway changes is by visual inspections. Even when visual inspections are performed, depending on the damage already occurred and/or frequency of the inspections, it is possible that existing or pending railway shifting may be missed or not identified timely enough.